Resolution issue with kvm switch

Tom Winterhalder t.winterhalder at
Thu Jul 5 13:04:14 PDT 2007

> >  Hi all,
> >  I have several systems connected to a Level1 KVM switch. According
> > documentations this switch can handle resolutions up to 1920x1440.
> >
> >  Now I have connected several Linux systems to this switch with different
> > graphic cards (ATI and Intel). Directly connected to my monitor (HP LP2465)
> > I get a resolution of 1920x1200 with all the systems. As soon as I connect
> > the systems to the switch and restart X I only get a resolution of
> > 1280x1024. Without restarting X, just connecting my systems to the switch I
> > still have the resolution of 1920x1200.
> >
> >  Looking into the log files I can see, that the switch is reporting to
> > display resolutions of up to 1280x1024. So it is clearly a problem of the
> > switch not reporting correctly its capabilities. As I have no possibility to
> > upgrade the firmware of this switch I wonder if there is a way to override
> > these settings in xorg.conf.
> >
> >  I already tried different Modelines and Mode settings without any success.
> > Can anyone help me solving this issue?
> Add a monitor section to your config with the appropriate sync ranges

The monitor section was already there. So I added the following lines
(Values taken from monitor spec):

        HorizSync   30-94
        VertRefresh 48-85

> and modes for your monitor 

How do I insert the correct modes here?  Using Modeline? Every Modeline
I use lets X crash immediately after starting it.

> then specify the modes you want in the
> display sub-section of the screen section of your config.  That should
> do the trick.

My screen section looks like the following including the modes.
Section "Screen"
        Identifier "aticonfig-Screen[0]"
        Device     "aticonfig-Device[0]"
        Monitor    "aticonfig-Monitor[0]"
        DefaultDepth     24
        SubSection "Display"
                Viewport   0 0
                Depth     24
                Modes   "1920x1200" "1600x1200" "1280x1024"

Best regards,
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